In accordance with the developments of recent years, there is a need for small-sized and highly dense memories. For example, such memory needs are required for magnetic recording units, which are designed with high density magnetic recording and downsizing development objectives. For realizing the high density recording objective, it is necessary to provide a recording medium having a highly coercive force sufficient for the minute magnetic domains that are recorded to stably exist, and a high-performance magnetic head formed from a material capable of achieving such recording on the medium. In order to magnetize the highly coercive medium sufficiently for recording the signals, it is necessary to use a magnetic head material having a high saturation magnetization capable of establishing an intense magnetic field. This magnetic material has conventionally been a Co-series amorphous alloy, an FeAlSi series (Sendust) alloy or the like.
At present, the magnetic material proposed to have such a high saturation magnetization is exemplified by an Fe--C alloy or an Fe--N alloy. These magnetic materials are subjected to a heat treatment at a constant temperature in an inert gas flow of argon or nitrogen, while being exposed to a magnetic field of about 3 to 10 KOe, if necessary, so that the soft magnetic properties may be developed. In case the magnetic head is the metal-in-gap (MIG) type head, its manufacturing process includes a glass bonding step at a bonding temperature that determines the temperature of the heat treatment. Since the soft magnetic properties of the magnetic film depend upon the small sized crystal grains to separate out, the crystal grain size has to be controlled in order to form a magnetic film having excellent soft magnetic properties. Moreover, since, these magnetic materials are composed mainly of Fe, they react with oxygen and moisture in the atmosphere to produce hydroxides or oxides that cause the magnetic properties to fluctuate, especially the coercive force and/or saturation magnetization properties. Accordingly, the performance of the magnetic head deteriorates.
When a magnetic head formed of the aforementioned magnetic material is used in practice, it is necessary to suppress fluctuations in its magnetic properties. As a result, magnetic alloys have been proposed that contain a relatively large concentration of C, as expressed by a composition formula of Fe(Ti, Zr, Hf, Nb, Ta, Mo, W)C, and as disclosed in Japanese Patent Laid-Open No. 20444/1991, or a relatively large concentration of Fe(Zr, Hf, Ti, Nb, Ta, V, Mo, W)N, as disclosed in Japanese Patent Laid-Open No. 275605/1991.